The railroad industry has tried for years to develop a satisfactory mechanism for lubricating the flange of railroad car wheels to reduce both rail and wheel wear that occurs as the flange rubs on the sides of the rails. The friction between wheel flanges and the rails is readily apparent from the squealing sound produced as a train rounds a curve; however, wear also occurs on straightaway sections of the track as the cars shift from side to side, bringing the rims of the wheels into contact with the sides of the rail.
Prior attempts to develop a mechanism to lubricate the wheels and rail have generally been unsuccessful because of the difficulty of applying a properly metered quantity of oil or grease to the wheel rim, while avoiding lubricant flow onto the portion of the wheel that runs on the top crown of the rail. When lubricant applied to the rim inadvertently runs onto the tread portion of the wheel, it tends to coat the rail crown, reducing the driving friction of the locomotive wheels, and impairing the ability of the railcar brakes to stop the train within a safe distance.
Most prior art lubricant applicators have included some form of pump and metering mechanism to supply oil or grease to the rim of the wheel in a metered flow. An example of such an applicator is disclosed in U.S. Pat. No. 3,783,971, wherein an applicator wheel is rotatably driven by the rail wheel, and is connected to drive an axially reciprocating piston. As the piston reciprocates within a chamber, it pumps oil from a supply through a restriction passage and onto a felt wick that is disposed in a groove around the circumference of the applicator wheel. The oil is thus applied by the felt wick to the railcar wheel as the car rolls down the track. A slotted link and pawl arrangement drives the piston to pump oil, regardless of the rotational direction of the applicator wheel.
Even if successful in properly metering oil or grease onto the rim of a wheel, such an applicator cannot prevent the oil from flowing onto adjacent surfaces of the wheel and eventually finding its way to the crown of the rail where it is likely to cause unacceptable slippage. Furthermore, if applied at too heavy a flow rate, the lubricant is likely to be flung from the wheel onto the undersurface of the railcar, and into the track-side environment, thereby creating a pollution problem.
In attempting to avoid the above problems, solid lubricant sticks have been developed in the prior art for use in applying a lubricating film to the flanges of rail car wheels. One of the commerically available lubricating sticks includes a ctalytically cured molybdenum disulfide compound molded in a cylindrical foil wrapper. The lubricating stick is mounted in a tubular applicator and is biased against the flange of a rail car wheel by a weight.
A similar stick or rod-type lubricant comprises a graphite base lubricating composition core enclosed in a molded "electric furnace" graphite shell. The graphite stick is placed in a tubular applicator and is biased against the wheel flange with a helical coil spring.
The dry lubricant sticks described above overcome some of the problems associated with lubricating rail car wheels using conventional oil or grease; however, they fail to provide a complete solution to the problem. Both types of dry lubricant sticks are fragile, being made of hard, brittle materials, which tend to break easily. Accordingly, a solid lubricant composition has been developed which is useful for lubricating rail car wheels, and is disclosed in the commonly assigned U.S. patent application, Ser. No. 72,097, filed July 10, 1987. The solid lubricant described in this patent application can be molded into rectangular blocks of various dimension that are ideally suited for applying a thin film of lubricant to the flanges of wheels on rail transit cars. Such cars receive weekly maintenance during which any worn blocks of solid lubricant composition might easily be replaced. None of the prior art solid lubricant applicators involving tubes useful for applying graphite rods are adapted for applying a rectangular block of the solid lubricant composition. The present invention provides a relatively low cost applicable for use with the solid lubricant blocks that is easily mounted on almost any style of transit rail car.